Hypoglycemia Treatment (Blood Glucose ~40 mg/dL)

Definition & Severity

Acute Emergency Treatment

If Patient is Conscious and Can Swallow

• 4-5 glucose tablets
• 150 mL (half a cup) of fruit juice or regular soda
• 1 tablespoon of sugar or honey
• 40% dextrose gel (sublingual - useful in resource-limited settings)

Note: Protein (peanut butter, cheese) and pure fructose do NOT effectively raise blood glucose. Avoid them for acute treatment. - Tintinalli's Emergency Medicine, p. 1463

If Patient Has Altered Mental Status / Cannot Swallow

• 50% Dextrose (D50W): 50 mL IV bolus (= 25 g glucose)
• Repeat after 15 min if hypoglycemia persists
• Once blood glucose reaches 70 mg/dL and consciousness returns, give oral carbohydrates
• If still unconscious after normalization: 5% Dextrose continuous IV infusion to maintain BG >100 mg/dL
• Check blood glucose every 30 minutes for the first 2 hours

• Tintinalli's Emergency Medicine, p. 1474

If IV Access Unavailable

• Onset: 10-15 minutes
• Available as emergency kit (IM) or intranasal formulation (newer option)
• Caution: ineffective in glycogen-depleted patients (starvation, alcohol-related); may cause nausea/vomiting and rebound hypoglycemia - monitor BG after administration

• Goldman-Cecil Medicine, p. 2497

Special Case: Sulfonylurea-Induced Hypoglycemia

• Suppresses insulin secretion immediately
• Superior to glucose and diazoxide in this setting
• Hemodialysis/charcoal hemoperfusion are NOT routinely recommended

• Tintinalli's Emergency Medicine, p. 1474

Monitoring After Treatment

• Check BG every 30 minutes x 2 hours
• Watch for rebound hypoglycemia (especially with glucagon or long-acting insulin overdose)
• Patients with significant long-acting insulin overdose should be admitted for monitoring
• If no response to IV glucose, consider underlying causes: sepsis, insulinoma, hepatic failure, adrenal insufficiency, toxin

Symptoms to Recognize (Why BG 40 is Dangerous)

Beta-blockers mask adrenergic symptoms and contribute to hypoglycemic unawareness - Tintinalli's Emergency Medicine, p. 1463

Summary Algorithm

BG = 40 mg/dL
    |
    ├─ Conscious, can swallow? → 15-20 g oral glucose → recheck in 15 min
    |
    ├─ Altered mental status, IV access? → D50W 50 mL IV bolus → repeat PRN
    |
    └─ No IV access? → Glucagon 1 mg IM (or intranasal)
                        → Monitor for rebound hypoglycemia

D5W (5% Dextrose in Water) - Complete Overview

Composition

• Washington Manual of Medical Therapeutics, p. 2281

Tonicity - Key Concept

• Only 100-150 mL (10-15%) stays in the ECF/plasma
• The rest distributes throughout all body fluid compartments (intracellular + extracellular)

Clinical Indications

In Hypoglycemia (Relevant to BG = 40 mg/dL)

• If patient remains unconscious or NPO, run D5W continuous infusion to maintain BG >100 mg/dL
• Check blood glucose every 30 minutes
• Titrate infusion rate down as glucose stabilizes

Important Cautions

• Not for volume resuscitation - use isotonic saline (0.9% NaCl) or Lactated Ringer's instead
• Hypernatremia correction - useful but must correct slowly (risk of cerebral edema if too rapid)
• Hypokalemia risk - dextrose stimulates insulin release, driving K+ into cells; can paradoxically worsen hypokalemia if KCl is mixed in D5W
• Not for patients with increased ICP - free water may worsen cerebral edema
• Hyperglycemia risk - especially in critically ill patients; monitor BG closely

Common Combinations

• Washington Manual of Medical Therapeutics | Schwartz's Principles of Surgery | Brenner & Rector's The Kidney

Injection Thiamine 300 mg

What It Is

Why It's Given Before Glucose (Critical Point)

Rule: Always give thiamine before or alongside IV dextrose in any patient with suspected thiamine deficiency (altered consciousness, alcoholism, malnutrition).

• Plum & Posner's Diagnosis and Treatment of Stupor and Coma, p. 538

Indications for Inj. Thiamine 300 mg

Dosing Protocol

Prophylactic (High-Risk Patients)

• Maudsley Prescribing Guidelines in Psychiatry (15th ed.), p. 512

Suspected Wernicke's Encephalopathy (Treatment)

• Transfer to medical unit for IV thiamine
• Continue until symptoms resolve
• Classic dose: 200-500 mg IV TDS (three times daily) in confirmed/suspected Wernicke's
• Older teaching: 100 mg IV/IM as minimum before glucose

Classic Triad of Wernicke's Encephalopathy (Often Incomplete)

If untreated, Wernicke's encephalopathy progresses to Korsakoff's syndrome - permanent memory impairment, confabulation, personality changes. - Maudsley Guidelines, p. 512

Risk Factors for Thiamine Deficiency

• Alcohol dependence (reduced intake + reduced absorption)
• Acute withdrawal
• Malnourishment / low BMI (<18)
• Decompensated liver disease
• Prolonged vomiting, diarrhoea
• Previous Wernicke's encephalopathy
• Peripheral neuropathy
• Homelessness

Oral vs. Injectable Thiamine

Connection to the Hypoglycemia Context (BG = 40)

• If there is any suspicion of alcoholism or malnutrition - give thiamine 100-300 mg IV/IM first (or simultaneously)
• Do not delay glucose if the patient is critically hypoglycemic - give both together

The "coma cocktail" principle: Dextrose + Thiamine (+ Naloxone if opioid suspected) for altered consciousness of unknown cause.

• Plum & Posner's Diagnosis and Treatment of Stupor and Coma, p. 538 | Maudsley Prescribing Guidelines, p. 512

D25W (25% Dextrose in Water)

Composition

Why D25W? - Comparing Dextrose Concentrations

Dosing in Hypoglycemia (ED Protocol)

For an infant or child - D25W 2 mL/kg IV delivers the same glucose dose as D50W 1 mL/kg but at half the osmolality, reducing vein irritation. - Tintinalli's Emergency Medicine, p. 1009

Why NOT D50W in Children?

• Extreme hypertonicity can cause venous sclerosis and tissue necrosis if extravasation occurs
• Risk of rebound hypoglycemia due to surge in insulin secretion
• Higher risk of hyperglycemia causing osmotic injury

D10W is preferred through small-gauge peripheral IVs. Higher dextrose concentrations (D25, D50) may be given via intraosseous (IO) if needed. - Tintinalli's Emergency Medicine, Pediatric Drug Dosing Table

How to Prepare D25W at Bedside

• Mix 50 mL of D50W + 50 mL sterile water = 100 mL of D25W
• Or dilute D50W 1:1 with 0.9% normal saline (gives ~D25 with some sodium)

Key Cautions

In Context: Hypoglycemia (BG = 40 mg/dL) Treatment Summary

• Tintinalli's Emergency Medicine, p. 1009

D5W vs D25W for Hypoglycemia Treatment

Why D5W Cannot Replace D25W for a Bolus

1. Grossly Insufficient Glucose Dose

• For a child, 2 mL/kg D25W = 0.5 g/kg glucose - a therapeutic bolus dose
• To deliver the same glucose with D5W, you'd need 10 mL/kg - a 5x larger volume
• Giving 10 mL/kg of fluid rapidly risks fluid overload, especially in small children

2. Too Slow to Correct Acute Hypoglycemia

• D5W at any practical rate takes too long to raise blood glucose in a symptomatic patient (BG = 40 mg/dL)
• A concentrated bolus is needed to rapidly correct neuroglycopenia

3. D5W Behaves as Free Water

• Once dextrose is metabolized, D5W distributes as free water across all fluid compartments
• Only ~10-15% remains in the vascular space - it does not efficiently raise blood glucose quickly

When D5W IS Appropriate

Practical Summary

D5W is a maintenance fluid. D25W (and D50W) are rescue/bolus fluids for hypoglycemia.

• Dilute D50W 1:1 with sterile water at bedside → gives D25W
• Or use D10W at 5 mL/kg (for neonates/infants) - acceptable alternative
• Never substitute D5W for an acute hypoglycemia bolus

D25W STAT - Dose & Rate

How Much to Give

• Tintinalli's Emergency Medicine, p. 1008 | Sabiston Textbook of Surgery, p. 831

How Fast to Give It (Rate)

Step-by-Step Protocol

STEP 1 → Check BG (confirm hypoglycemia, BG ~40 mg/dL)
STEP 2 → Give thiamine first if malnourished/alcoholic
STEP 3 → D25W 2 mL/kg IV BOLUS over 1-3 minutes (STAT)
STEP 4 → Recheck BG in 15 minutes
STEP 5 → If BG still low → repeat bolus
STEP 6 → Once BG >70 mg/dL → start D10W maintenance infusion
           (6-8 mg/kg/min = approximately 3.6-4.8 mL/kg/hr of D10W)
STEP 7 → Check BG every 30 minutes for 2 hours

Key Points

• STAT means rapid bolus - not a slow drip. The entire calculated dose is pushed over 1-3 minutes.
• Use the largest bore peripheral IV available, or IO if no IV access
• Avoid small-gauge IVs if possible - D25W is hypertonic and can cause vein irritation/extravasation
• After the bolus, always follow with D10W maintenance to prevent rebound hypoglycemia
• Some experts prefer 0.25 g/kg (= 1 mL/kg D25W) as a smaller bolus to minimize reactive hyperinsulinism and rebound hypoglycemia - acceptable especially in neonates

• Tintinalli's Emergency Medicine, p. 1008 | Sabiston Textbook of Surgery, p. 831

Interpretation

What to Do Now

1. If Patient is on D10W Maintenance Infusion

• Reduce the infusion rate by 30-50%
• Do NOT stop it abruptly - risk of rebound hypoglycemia, especially if:
  • Sulfonylurea-induced hypoglycemia (insulin secretion still stimulated)
  • Insulin overdose (long-acting insulin still active)
  • Underlying cause not yet resolved

2. If Patient is Conscious and Can Eat

• Start oral feeds - give a mixed meal (complex carbohydrates + protein)
• Can wean IV dextrose as oral intake is established
• Oral feeding is the best way to stabilize glucose going forward

3. Do NOT give Insulin

• BG 205 is not dangerous in this acute post-hypoglycemia context
• Giving insulin risks precipitating hypoglycemia again
• Let the glucose come down naturally

Monitoring Plan

Watch For Rebound Hypoglycemia

In sulfonylurea-induced cases, even after BG normalizes, continue monitoring for 24-48 hours - rebound is common and can be severe.

Summary

• Reduce dextrose infusion
• Start oral feeds if possible
• Recheck BG every 30 minutes
• Do NOT stop monitoring - the underlying cause still determines how long dextrose support is needed
• Avoid insulin for BG 205 in this context